From ee443996a35c1e04f210cafd43d5a98d41e46085 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Wed, 5 Mar 2008 07:08:09 -0600 Subject: 9p: Documentation updates The kernel-doc comments of much of the 9p system have been in disarray since reorganization. This patch fixes those problems, adds additional documentation and a template book which collects the 9p information. Signed-off-by: Eric Van Hensbergen --- net/9p/conv.c | 128 ++++++++++++++++++++++++++++++++++++++++- net/9p/error.c | 11 +++- net/9p/fcprint.c | 8 +++ net/9p/mod.c | 7 +-- net/9p/trans_fd.c | 146 ++++++++++++++++++++++++++++++++++++++++------- net/9p/trans_virtio.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++---- net/9p/util.c | 32 +++++++++-- 7 files changed, 441 insertions(+), 46 deletions(-) (limited to 'net') diff --git a/net/9p/conv.c b/net/9p/conv.c index 3fe35d532c8..44547201f5b 100644 --- a/net/9p/conv.c +++ b/net/9p/conv.c @@ -197,7 +197,7 @@ static void buf_get_qid(struct cbuf *bufp, struct p9_qid *qid) /** * p9_size_wstat - calculate the size of a variable length stat struct - * @stat: metadata (stat) structure + * @wstat: metadata (stat) structure * @dotu: non-zero if 9P2000.u * */ @@ -511,6 +511,12 @@ p9_create_common(struct cbuf *bufp, u32 size, u8 id) return fc; } +/** + * p9_set_tag - set the tag field of an &p9_fcall structure + * @fc: fcall structure to set tag within + * @tag: tag id to set + */ + void p9_set_tag(struct p9_fcall *fc, u16 tag) { fc->tag = tag; @@ -518,6 +524,12 @@ void p9_set_tag(struct p9_fcall *fc, u16 tag) } EXPORT_SYMBOL(p9_set_tag); +/** + * p9_create_tversion - allocates and creates a T_VERSION request + * @msize: requested maximum data size + * @version: version string to negotiate + * + */ struct p9_fcall *p9_create_tversion(u32 msize, char *version) { int size; @@ -542,6 +554,16 @@ error: } EXPORT_SYMBOL(p9_create_tversion); +/** + * p9_create_tauth - allocates and creates a T_AUTH request + * @afid: handle to use for authentication protocol + * @uname: user name attempting to authenticate + * @aname: mount specifier for remote server + * @n_uname: numeric id for user attempting to authneticate + * @dotu: 9P2000.u extension flag + * + */ + struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname, u32 n_uname, int dotu) { @@ -580,6 +602,18 @@ error: } EXPORT_SYMBOL(p9_create_tauth); +/** + * p9_create_tattach - allocates and creates a T_ATTACH request + * @fid: handle to use for the new mount point + * @afid: handle to use for authentication protocol + * @uname: user name attempting to attach + * @aname: mount specifier for remote server + * @n_uname: numeric id for user attempting to attach + * @n_uname: numeric id for user attempting to attach + * @dotu: 9P2000.u extension flag + * + */ + struct p9_fcall * p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname, u32 n_uname, int dotu) @@ -616,6 +650,12 @@ error: } EXPORT_SYMBOL(p9_create_tattach); +/** + * p9_create_tflush - allocates and creates a T_FLUSH request + * @oldtag: tag id for the transaction we are attempting to cancel + * + */ + struct p9_fcall *p9_create_tflush(u16 oldtag) { int size; @@ -639,6 +679,15 @@ error: } EXPORT_SYMBOL(p9_create_tflush); +/** + * p9_create_twalk - allocates and creates a T_FLUSH request + * @fid: handle we are traversing from + * @newfid: a new handle for this transaction + * @nwname: number of path elements to traverse + * @wnames: array of path elements + * + */ + struct p9_fcall *p9_create_twalk(u32 fid, u32 newfid, u16 nwname, char **wnames) { @@ -677,6 +726,13 @@ error: } EXPORT_SYMBOL(p9_create_twalk); +/** + * p9_create_topen - allocates and creates a T_OPEN request + * @fid: handle we are trying to open + * @mode: what mode we are trying to open the file in + * + */ + struct p9_fcall *p9_create_topen(u32 fid, u8 mode) { int size; @@ -701,6 +757,19 @@ error: } EXPORT_SYMBOL(p9_create_topen); +/** + * p9_create_tcreate - allocates and creates a T_CREATE request + * @fid: handle of directory we are trying to create in + * @name: name of the file we are trying to create + * @perm: permissions for the file we are trying to create + * @mode: what mode we are trying to open the file in + * @extension: 9p2000.u extension string (for special files) + * @dotu: 9p2000.u enabled flag + * + * Note: Plan 9 create semantics include opening the resulting file + * which is why mode is included. + */ + struct p9_fcall *p9_create_tcreate(u32 fid, char *name, u32 perm, u8 mode, char *extension, int dotu) { @@ -736,6 +805,13 @@ error: } EXPORT_SYMBOL(p9_create_tcreate); +/** + * p9_create_tread - allocates and creates a T_READ request + * @fid: handle of the file we are trying to read + * @offset: offset to start reading from + * @count: how many bytes to read + */ + struct p9_fcall *p9_create_tread(u32 fid, u64 offset, u32 count) { int size; @@ -761,6 +837,17 @@ error: } EXPORT_SYMBOL(p9_create_tread); +/** + * p9_create_twrite - allocates and creates a T_WRITE request from the kernel + * @fid: handle of the file we are trying to write + * @offset: offset to start writing at + * @count: how many bytes to write + * @data: data to write + * + * This function will create a requst with data buffers from the kernel + * such as the page cache. + */ + struct p9_fcall *p9_create_twrite(u32 fid, u64 offset, u32 count, const char *data) { @@ -794,6 +881,16 @@ error: } EXPORT_SYMBOL(p9_create_twrite); +/** + * p9_create_twrite_u - allocates and creates a T_WRITE request from userspace + * @fid: handle of the file we are trying to write + * @offset: offset to start writing at + * @count: how many bytes to write + * @data: data to write + * + * This function will create a request with data buffers from userspace + */ + struct p9_fcall *p9_create_twrite_u(u32 fid, u64 offset, u32 count, const char __user *data) { @@ -827,6 +924,14 @@ error: } EXPORT_SYMBOL(p9_create_twrite_u); +/** + * p9_create_tclunk - allocate a request to forget about a file handle + * @fid: handle of the file we closing or forgetting about + * + * clunk is used both to close open files and to discard transient handles + * which may be created during meta-data operations and hierarchy traversal. + */ + struct p9_fcall *p9_create_tclunk(u32 fid) { int size; @@ -850,6 +955,12 @@ error: } EXPORT_SYMBOL(p9_create_tclunk); +/** + * p9_create_tremove - allocate and create a request to remove a file + * @fid: handle of the file or directory we are removing + * + */ + struct p9_fcall *p9_create_tremove(u32 fid) { int size; @@ -873,6 +984,12 @@ error: } EXPORT_SYMBOL(p9_create_tremove); +/** + * p9_create_tstat - allocate and populate a request for attributes + * @fid: handle of the file or directory we are trying to get the attributes of + * + */ + struct p9_fcall *p9_create_tstat(u32 fid) { int size; @@ -896,6 +1013,14 @@ error: } EXPORT_SYMBOL(p9_create_tstat); +/** + * p9_create_tstat - allocate and populate a request to change attributes + * @fid: handle of the file or directory we are trying to change + * @wstat: &p9_stat structure with attributes we wish to set + * @dotu: 9p2000.u enabled flag + * + */ + struct p9_fcall *p9_create_twstat(u32 fid, struct p9_wstat *wstat, int dotu) { @@ -922,3 +1047,4 @@ error: return fc; } EXPORT_SYMBOL(p9_create_twstat); + diff --git a/net/9p/error.c b/net/9p/error.c index 64104b9cb42..388770c3631 100644 --- a/net/9p/error.c +++ b/net/9p/error.c @@ -33,6 +33,13 @@ #include #include +/** + * struct errormap - map string errors from Plan 9 to Linux numeric ids + * @name: string sent over 9P + * @val: numeric id most closely representing @name + * @namelen: length of string + * @list: hash-table list for string lookup + */ struct errormap { char *name; int val; @@ -177,8 +184,7 @@ static struct errormap errmap[] = { }; /** - * p9_error_init - preload - * @errstr: error string + * p9_error_init - preload mappings into hash list * */ @@ -206,6 +212,7 @@ EXPORT_SYMBOL(p9_error_init); /** * errstr2errno - convert error string to error number * @errstr: error string + * @len: length of error string * */ diff --git a/net/9p/fcprint.c b/net/9p/fcprint.c index 40244fbd9b0..53dd8e28dd8 100644 --- a/net/9p/fcprint.c +++ b/net/9p/fcprint.c @@ -142,6 +142,14 @@ p9_printdata(char *buf, int buflen, u8 *data, int datalen) return p9_dumpdata(buf, buflen, data, datalen < 16?datalen:16); } +/** + * p9_printfcall - decode and print a protocol structure into a buffer + * @buf: buffer to deposit decoded structure into + * @buflen: available space in buffer + * @fc: protocol rpc structure of type &p9_fcall + * @extended: whether or not session is operating with extended protocol + */ + int p9_printfcall(char *buf, int buflen, struct p9_fcall *fc, int extended) { diff --git a/net/9p/mod.c b/net/9p/mod.c index c285aab2af0..c6d9695949e 100644 --- a/net/9p/mod.c +++ b/net/9p/mod.c @@ -39,9 +39,6 @@ module_param_named(debug, p9_debug_level, uint, 0); MODULE_PARM_DESC(debug, "9P debugging level"); #endif -extern int p9_mux_global_init(void); -extern void p9_mux_global_exit(void); - /* * Dynamic Transport Registration Routines * @@ -52,7 +49,7 @@ static struct p9_trans_module *v9fs_default_transport; /** * v9fs_register_trans - register a new transport with 9p - * @m - structure describing the transport module and entry points + * @m: structure describing the transport module and entry points * */ void v9fs_register_trans(struct p9_trans_module *m) @@ -65,7 +62,7 @@ EXPORT_SYMBOL(v9fs_register_trans); /** * v9fs_match_trans - match transport versus registered transports - * @arg: string identifying transport + * @name: string identifying transport * */ struct p9_trans_module *v9fs_match_trans(const substring_t *name) diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index f624dff7685..c6eda999fa7 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -47,12 +47,29 @@ #define SCHED_TIMEOUT 10 #define MAXPOLLWADDR 2 +/** + * struct p9_fd_opts - per-transport options + * @rfd: file descriptor for reading (trans=fd) + * @wfd: file descriptor for writing (trans=fd) + * @port: port to connect to (trans=tcp) + * + */ + struct p9_fd_opts { int rfd; int wfd; u16 port; }; + +/** + * struct p9_trans_fd - transport state + * @rd: reference to file to read from + * @wr: reference of file to write to + * @conn: connection state reference + * + */ + struct p9_trans_fd { struct file *rd; struct file *wr; @@ -90,10 +107,24 @@ enum { }; struct p9_req; - typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a); + +/** + * struct p9_req - fd mux encoding of an rpc transaction + * @lock: protects req_list + * @tag: numeric tag for rpc transaction + * @tcall: request &p9_fcall structure + * @rcall: response &p9_fcall structure + * @err: error state + * @cb: callback for when response is received + * @cba: argument to pass to callback + * @flush: flag to indicate RPC has been flushed + * @req_list: list link for higher level objects to chain requests + * + */ + struct p9_req { - spinlock_t lock; /* protect request structure */ + spinlock_t lock; int tag; struct p9_fcall *tcall; struct p9_fcall *rcall; @@ -104,7 +135,39 @@ struct p9_req { struct list_head req_list; }; -struct p9_mux_poll_task; +struct p9_mux_poll_task { + struct task_struct *task; + struct list_head mux_list; + int muxnum; +}; + +/** + * struct p9_conn - fd mux connection state information + * @lock: protects mux_list (?) + * @mux_list: list link for mux to manage multiple connections (?) + * @poll_task: task polling on this connection + * @msize: maximum size for connection (dup) + * @extended: 9p2000.u flag (dup) + * @trans: reference to transport instance for this connection + * @tagpool: id accounting for transactions + * @err: error state + * @equeue: event wait_q (?) + * @req_list: accounting for requests which have been sent + * @unsent_req_list: accounting for requests that haven't been sent + * @rcall: current response &p9_fcall structure + * @rpos: read position in current frame + * @rbuf: current read buffer + * @wpos: write position for current frame + * @wsize: amount of data to write for current frame + * @wbuf: current write buffer + * @poll_wait: array of wait_q's for various worker threads + * @poll_waddr: ???? + * @pt: poll state + * @rq: current read work + * @wq: current write work + * @wsched: ???? + * + */ struct p9_conn { spinlock_t lock; /* protect lock structure */ @@ -132,11 +195,16 @@ struct p9_conn { unsigned long wsched; }; -struct p9_mux_poll_task { - struct task_struct *task; - struct list_head mux_list; - int muxnum; -}; +/** + * struct p9_mux_rpc - fd mux rpc accounting structure + * @m: connection this request was issued on + * @err: error state + * @tcall: request &p9_fcall + * @rcall: response &p9_fcall + * @wqueue: wait queue that client is blocked on for this rpc + * + * Bug: isn't this information duplicated elsewhere like &p9_req + */ struct p9_mux_rpc { struct p9_conn *m; @@ -207,10 +275,12 @@ static void p9_mux_put_tag(struct p9_conn *m, u16 tag) /** * p9_mux_calc_poll_procs - calculates the number of polling procs - * based on the number of mounted v9fs filesystems. + * @muxnum: number of mounts * + * Calculation is based on the number of mounted v9fs filesystems. * The current implementation returns sqrt of the number of mounts. */ + static int p9_mux_calc_poll_procs(int muxnum) { int n; @@ -331,12 +401,11 @@ static void p9_mux_poll_stop(struct p9_conn *m) /** * p9_conn_create - allocate and initialize the per-session mux data - * Creates the polling task if this is the first session. + * @trans: transport structure * - * @trans - transport structure - * @msize - maximum message size - * @extended - extended flag + * Note: Creates the polling task if this is the first session. */ + static struct p9_conn *p9_conn_create(struct p9_trans *trans) { int i, n; @@ -406,7 +475,10 @@ static struct p9_conn *p9_conn_create(struct p9_trans *trans) /** * p9_mux_destroy - cancels all pending requests and frees mux resources + * @m: mux to destroy + * */ + static void p9_conn_destroy(struct p9_conn *m) { P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m, @@ -429,9 +501,14 @@ static void p9_conn_destroy(struct p9_conn *m) } /** - * p9_pollwait - called by files poll operation to add v9fs-poll task - * to files wait queue + * p9_pollwait - add poll task to the wait queue + * @filp: file pointer being polled + * @wait_address: wait_q to block on + * @p: poll state + * + * called by files poll operation to add v9fs-poll task to files wait queue */ + static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) { @@ -462,7 +539,10 @@ p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) /** * p9_poll_mux - polls a mux and schedules read or write works if necessary + * @m: connection to poll + * */ + static void p9_poll_mux(struct p9_conn *m) { int n; @@ -499,9 +579,14 @@ static void p9_poll_mux(struct p9_conn *m) } /** - * p9_poll_proc - polls all v9fs transports for new events and queues - * the appropriate work to the work queue + * p9_poll_proc - poll worker thread + * @a: thread state and arguments + * + * polls all v9fs transports for new events and queues the appropriate + * work to the work queue + * */ + static int p9_poll_proc(void *a) { struct p9_conn *m, *mtmp; @@ -527,7 +612,10 @@ static int p9_poll_proc(void *a) /** * p9_write_work - called when a transport can send some data + * @work: container for work to be done + * */ + static void p9_write_work(struct work_struct *work) { int n, err; @@ -638,7 +726,10 @@ static void process_request(struct p9_conn *m, struct p9_req *req) /** * p9_read_work - called when there is some data to be read from a transport + * @work: container of work to be done + * */ + static void p9_read_work(struct work_struct *work) { int n, err; @@ -793,7 +884,9 @@ error: * @tc: request to be sent * @cb: callback function to call when response is received * @cba: parameter to pass to the callback function + * */ + static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc, p9_conn_req_callback cb, void *cba) @@ -961,10 +1054,12 @@ p9_conn_rpc_cb(struct p9_req *req, void *a) /** * p9_fd_rpc- sends 9P request and waits until a response is available. * The function can be interrupted. - * @m: mux data + * @t: transport data * @tc: request to be sent * @rc: pointer where a pointer to the response is stored + * */ + int p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) { @@ -1041,8 +1136,10 @@ p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) * @m: mux data * @tc: request to be sent * @cb: callback function to be called when response arrives - * @cba: value to pass to the callback function + * @a: value to pass to the callback function + * */ + int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc, p9_conn_req_callback cb, void *a) { @@ -1065,7 +1162,9 @@ int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc, * p9_conn_cancel - cancel all pending requests with error * @m: mux data * @err: error code + * */ + void p9_conn_cancel(struct p9_conn *m, int err) { struct p9_req *req, *rtmp; @@ -1099,7 +1198,7 @@ void p9_conn_cancel(struct p9_conn *m, int err) /** * v9fs_parse_options - parse mount options into session structure * @options: options string passed from mount - * @v9ses: existing v9fs session information + * @opts: transport-specific structure to parse options into * */ @@ -1193,11 +1292,12 @@ static int p9_socket_open(struct p9_trans *trans, struct socket *csocket) /** * p9_fd_read- read from a fd - * @v9ses: session information + * @trans: transport instance state * @v: buffer to receive data into * @len: size of receive buffer * */ + static int p9_fd_read(struct p9_trans *trans, void *v, int len) { int ret; @@ -1220,11 +1320,12 @@ static int p9_fd_read(struct p9_trans *trans, void *v, int len) /** * p9_fd_write - write to a socket - * @v9ses: session information + * @trans: transport instance state * @v: buffer to send data from * @len: size of send buffer * */ + static int p9_fd_write(struct p9_trans *trans, void *v, int len) { int ret; @@ -1296,6 +1397,7 @@ end: * @trans: private socket structure * */ + static void p9_fd_close(struct p9_trans *trans) { struct p9_trans_fd *ts; diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index de7a9f532ed..0bab1f23590 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -55,23 +55,69 @@ static int chan_index; #define P9_INIT_MAXTAG 16 -#define REQ_STATUS_IDLE 0 -#define REQ_STATUS_SENT 1 -#define REQ_STATUS_RCVD 2 -#define REQ_STATUS_FLSH 3 + +/** + * enum p9_req_status_t - virtio request status + * @REQ_STATUS_IDLE: request slot unused + * @REQ_STATUS_SENT: request sent to server + * @REQ_STATUS_RCVD: response received from server + * @REQ_STATUS_FLSH: request has been flushed + * + * The @REQ_STATUS_IDLE state is used to mark a request slot as unused + * but use is actually tracked by the idpool structure which handles tag + * id allocation. + * + */ + +enum p9_req_status_t { + REQ_STATUS_IDLE, + REQ_STATUS_SENT, + REQ_STATUS_RCVD, + REQ_STATUS_FLSH, +}; + +/** + * struct p9_req_t - virtio request slots + * @status: status of this request slot + * @wq: wait_queue for the client to block on for this request + * + * The virtio transport uses an array to track outstanding requests + * instead of a list. While this may incurr overhead during initial + * allocation or expansion, it makes request lookup much easier as the + * tag id is a index into an array. (We use tag+1 so that we can accomodate + * the -1 tag for the T_VERSION request). + * This also has the nice effect of only having to allocate wait_queues + * once, instead of constantly allocating and freeing them. Its possible + * other resources could benefit from this scheme as well. + * + */ struct p9_req_t { int status; wait_queue_head_t *wq; }; -/* We keep all per-channel information in a structure. +/** + * struct virtio_chan - per-instance transport information + * @initialized: whether the channel is initialized + * @inuse: whether the channel is in use + * @lock: protects multiple elements within this structure + * @vdev: virtio dev associated with this channel + * @vq: virtio queue associated with this channel + * @tagpool: accounting for tag ids (and request slots) + * @reqs: array of request slots + * @max_tag: current number of request_slots allocated + * @sg: scatter gather list which is used to pack a request (protected?) + * + * We keep all per-channel information in a structure. * This structure is allocated within the devices dev->mem space. * A pointer to the structure will get put in the transport private. + * */ + static struct virtio_chan { - bool initialized; /* channel is initialized */ - bool inuse; /* channel is in use */ + bool initialized; + bool inuse; spinlock_t lock; @@ -86,7 +132,19 @@ static struct virtio_chan { struct scatterlist sg[VIRTQUEUE_NUM]; } channels[MAX_9P_CHAN]; -/* Lookup requests by tag */ +/** + * p9_lookup_tag - Lookup requests by tag + * @c: virtio channel to lookup tag within + * @tag: numeric id for transaction + * + * this is a simple array lookup, but will grow the + * request_slots as necessary to accomodate transaction + * ids which did not previously have a slot. + * + * Bugs: there is currently no upper limit on request slots set + * here, but that should be constrained by the id accounting. + */ + static struct p9_req_t *p9_lookup_tag(struct virtio_chan *c, u16 tag) { /* This looks up the original request by tag so we know which @@ -130,6 +188,15 @@ static unsigned int rest_of_page(void *data) return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE); } +/** + * p9_virtio_close - reclaim resources of a channel + * @trans: transport state + * + * This reclaims a channel by freeing its resources and + * reseting its inuse flag. + * + */ + static void p9_virtio_close(struct p9_trans *trans) { struct virtio_chan *chan = trans->priv; @@ -151,6 +218,19 @@ static void p9_virtio_close(struct p9_trans *trans) kfree(trans); } +/** + * req_done - callback which signals activity from the server + * @vq: virtio queue activity was received on + * + * This notifies us that the server has triggered some activity + * on the virtio channel - most likely a response to request we + * sent. Figure out which requests now have responses and wake up + * those threads. + * + * Bugs: could do with some additional sanity checking, but appears to work. + * + */ + static void req_done(struct virtqueue *vq) { struct virtio_chan *chan = vq->vdev->priv; @@ -169,6 +249,20 @@ static void req_done(struct virtqueue *vq) spin_unlock_irqrestore(&chan->lock, flags); } +/** + * pack_sg_list - pack a scatter gather list from a linear buffer + * @sg: scatter/gather list to pack into + * @start: which segment of the sg_list to start at + * @limit: maximum segment to pack data to + * @data: data to pack into scatter/gather list + * @count: amount of data to pack into the scatter/gather list + * + * sg_lists have multiple segments of various sizes. This will pack + * arbitrary data into an existing scatter gather list, segmenting the + * data as necessary within constraints. + * + */ + static int pack_sg_list(struct scatterlist *sg, int start, int limit, char *data, int count) @@ -189,6 +283,14 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data, return index-start; } +/** + * p9_virtio_rpc - issue a request and wait for a response + * @t: transport state + * @tc: &p9_fcall request to transmit + * @rc: &p9_fcall to put reponse into + * + */ + static int p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) { @@ -263,6 +365,16 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) return 0; } +/** + * p9_virtio_probe - probe for existence of 9P virtio channels + * @vdev: virtio device to probe + * + * This probes for existing virtio channels. At present only + * a single channel is in use, so in the future more work may need + * to be done here. + * + */ + static int p9_virtio_probe(struct virtio_device *vdev) { int err; @@ -307,11 +419,28 @@ fail: return err; } -/* This sets up a transport channel for 9p communication. Right now + +/** + * p9_virtio_create - allocate a new virtio channel + * @devname: string identifying the channel to connect to (unused) + * @args: args passed from sys_mount() for per-transport options (unused) + * @msize: requested maximum packet size + * @extended: 9p2000.u enabled flag + * + * This sets up a transport channel for 9p communication. Right now * we only match the first available channel, but eventually we couldlook up * alternate channels by matching devname versus a virtio_config entry. * We use a simple reference count mechanism to ensure that only a single - * mount has a channel open at a time. */ + * mount has a channel open at a time. + * + * Bugs: doesn't allow identification of a specific channel + * to allocate, channels are allocated sequentially. This was + * a pragmatic decision to get things rolling, but ideally some + * way of identifying the channel to attach to would be nice + * if we are going to support multiple channels. + * + */ + static struct p9_trans * p9_virtio_create(const char *devname, char *args, int msize, unsigned char extended) @@ -360,6 +489,12 @@ p9_virtio_create(const char *devname, char *args, int msize, return trans; } +/** + * p9_virtio_remove - clean up resources associated with a virtio device + * @vdev: virtio device to remove + * + */ + static void p9_virtio_remove(struct virtio_device *vdev) { struct virtio_chan *chan = vdev->priv; diff --git a/net/9p/util.c b/net/9p/util.c index ef7215565d8..4d564604533 100644 --- a/net/9p/util.c +++ b/net/9p/util.c @@ -32,11 +32,23 @@ #include #include +/** + * struct p9_idpool - per-connection accounting for tag idpool + * @lock: protects the pool + * @pool: idr to allocate tag id from + * + */ + struct p9_idpool { spinlock_t lock; struct idr pool; }; +/** + * p9_idpool_create - create a new per-connection id pool + * + */ + struct p9_idpool *p9_idpool_create(void) { struct p9_idpool *p; @@ -52,6 +64,11 @@ struct p9_idpool *p9_idpool_create(void) } EXPORT_SYMBOL(p9_idpool_create); +/** + * p9_idpool_destroy - create a new per-connection id pool + * @p: idpool to destory + */ + void p9_idpool_destroy(struct p9_idpool *p) { idr_destroy(&p->pool); @@ -61,9 +78,9 @@ EXPORT_SYMBOL(p9_idpool_destroy); /** * p9_idpool_get - allocate numeric id from pool - * @p - pool to allocate from + * @p: pool to allocate from * - * XXX - This seems to be an awful generic function, should it be in idr.c with + * Bugs: This seems to be an awful generic function, should it be in idr.c with * the lock included in struct idr? */ @@ -94,9 +111,10 @@ EXPORT_SYMBOL(p9_idpool_get); /** * p9_idpool_put - release numeric id from pool - * @p - pool to allocate from + * @id: numeric id which is being released + * @p: pool to release id into * - * XXX - This seems to be an awful generic function, should it be in idr.c with + * Bugs: This seems to be an awful generic function, should it be in idr.c with * the lock included in struct idr? */ @@ -111,11 +129,13 @@ EXPORT_SYMBOL(p9_idpool_put); /** * p9_idpool_check - check if the specified id is available - * @id - id to check - * @p - pool + * @id: id to check + * @p: pool to check */ + int p9_idpool_check(int id, struct p9_idpool *p) { return idr_find(&p->pool, id) != NULL; } EXPORT_SYMBOL(p9_idpool_check); + -- cgit v1.2.3